


Experimental

by pregnantobsessions



Category: Harry Potter - J. K. Rowling
Genre: Accidental Voyeurism, Consensual Infidelity, F/M, Fertility Potion, Gangbang, Married Hinny, Multi, POV Hermione Granger, Pregnancy Kink, Unplanned Pregnancy, Unprotected Sex, Unspeakable Hermione Granger, Voyeurism, but it wasn't supposed to be sexy, mostly - Freeform, multiple pregnancy, porn with just enough plot to justify the situation, technical language in the beginning because this is an official situation, the watching is on purpose and consensual, totally on purpose in chapter 2
Language: English
Status: In-Progress
Published: 2020-02-27
Updated: 2020-04-30
Packaged: 2021-02-28 06:34:03
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,787
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22919281
Author URL: https://archiveofourown.org/users/pregnantobsessions/pseuds/pregnantobsessions
Summary: The Department of Mysteries is testing the ramifications of a new fertility potion.
Relationships: Anthony Goldstein/Ginny Weasley, Ernie Macmillan/Ginny Weasley, Ginny Weasley/Blaise Zabini, Harry Potter/Ginny Weasley, Hermione Granger/Harry Potter, Neville Longbottom/Ginny Weasley
Comments: 6
Kudos: 75





	1. Chapter 1

Hermione resituated herself in the observation booth following her lunch break, organizing her clipboard and preparing herself mentally before the next round began.

The Department was testing a newly developed fertility potion, which prompted a witch's body to immediately release four to seven ova in order to increase the chances of fertilization and implantation.

The question the Unspeakables were currently asking was whether it was possible for a witch taking this potion to become pregnant by more than one wizard at simultaneously. In order to test this, the Department had gathered volunteers. Each participating witch would, while taking the new potion, have intercourse with a group of five wizards. In order to ensure each man's sperm had equal opportunity to impregnate her, they would do so on a rotation in quick succession. In cruder terms, the each witch was to be gangbanged repeatedly until she was pregnant.

To maintain experimental integrity, an Unspeakable was required to watch each group, making notes on their activities and compliance with the procedure. This would be the fourth group Hermione observed today.

To further maintain integrity, all of the participants were required to live in the Department until the witch in their group was confirmed to be pregnant. This ensured their activities could be monitored around the clock, and no one would be able to muddle the procedure with _extracurricular_ intercourse.

Hermione looked at her clipboard, and read the parchments there for the first time.

_Experimental Group F: Ginevra M. Potter, Harry J. Potter, Blaise H. Zabini, Earnest B. Macmillan, Anthony R. Goldstein_

Hermione's mouth grew suddenly dry. Harry and Ginny knew she was an Unspeakable. Following the war, the Department as a whole had been required to abandon the masked hoods and code names for the public's safety and peace of mind. They hadn't told her, however, that they'd volunteered for the study. She'd just come from lunch with them, having met them to say goodbye before they left on a _trip of unknown length._ A trip that was apparently into the Department of Mysteries.

She swallowed. She could be a professional about this. They were good candidates, honestly. Ginny's family history with fertility was promising. Speaking of fertility, Hermione quickly reviewed each group member's results on the fertility tests they'd undergone, and signed the line on the form indicating she approved.

She then activated a rune, sending a notification to the waiting area. All six participants listen on her sheet entered the chamber wearing only house robes. They couldn't see her, though they knew they were being watched. Hermione wondered if her friends had asked for the name of the Unspeakable assigned to their group. Ginny carried a pink box, while each of the men carried blue ones. (Hermione had scoffed at the gender-normative color coding, but hadn't thrown a genuine snit. It was easy to remember, at least.) Each box contained doses of potions. In addition to the fertility potion Ginny would take, each of the wizards had a virility potion that would help them to recover more quickly post-orgasm. Every box also included a lust potion, which the participants could choose to take or not, in the event that someone needed help getting aroused. Hermione made notes on the parchment about which of them took it, unable to ignore the fact that neither Harry or Ginny felt the need. Apparently, they felt they were aroused enough.

Ginny laid down on the bed in the center of the Chamber after shedding her robe. Harry approached her first, his large cock jutting out ahead of him as they grinned saliciously at each other. Hermione shifted in her seat, slightly horrified to realize she was getting aroused herself. She didn't need to make any more notes for awhile unless something went wrong, so she didn't even have that to distract herself.

She hadn't been turned on at any point this morning! Harry was rubbing his cock against the folds of Ginny's sex, his mouth on her neck as she squirmed beneath him.

Hermione pressed her legs together and groaned softly. In truth, she had fantasized about Harry semi-regularly since she was young. Sometimes he was with her in her fantasies, and sometimes he fucked someone else while she watched _just like this._ The fact that Harry was hung wouldn't bes a deterrent at all.

She'd thought about Ginny, too. It started when Hermione first overheard her and Harry fucking without a silencing charm, but from there the redhead had become a large part of Hermione's realization that she was bisexual.

So Hermione didn't really stand a chance of maintaining an air of professionalism, watching her two most attractive friends act out one of her most secret fantasies. Harry was inside Ginny, now, fucking her in long, powerful strokes while working her clit with his thumb. She was flushed, color traveling down her neck and chest, over her peaked tits. She moaned constantly as Harry seemed to be speaking into her ear. The chamber was silenced, but Hermione was transfixed by the column of Ginny's throat as she tossed her head in ecstasy.

Ginny seemed to scream, and Harry's hips stilled almost entirely, pushed deeply inside his wife. Hermione wondered if the head of his cock reached Ginny's cervix, and thought that it probably did based on its size.

A rune on her desk lighting up startled Hermione from her lustful musings, and Hermione scolded herself. The lit rune indicated that someone - in this case, Harry - had ejaculated. She had been the one to tune it to respond only to the male orgasm.

Harry pulled his cock - softening because he hadn't taken the lust potion - out of Ginny and pressed an open-mouthed kiss to her abdomen before backing away. The other men in the chamber had circled around the couple while they fucked, and Macmillan took Harry's place between Ginny's legs.

Macmillan didn't seem to be quite as impressive sexually as Harry. Ginny was enjoying herself, but she wasn't lost in pleasure the way she had been while her husband fucked her. Perhaps the comparison was unfair - Harry had certainly had more time to learn Ginny's preferences. Ginny dropped her own hand to her clit. Macmillan had taken the lust potion, and was very consumed in chasing his own orgasm.

Harry approached Ginny from the direction of her head, and Hermione wondered if she was going to have to reprimand him for breaking procedure. He wasn't fully hard again yet, but he did seem to enjoy watching his wife get fucked with another man's cock. Harry didn't try to get Ginny to touch him, like Hermione had worried he would. Instead, he began plucking and twisting her nipples. Ginny's face screwed up in pain-pleasure, and Harry gave off her a cocky grin.

Macmillan came inside Ginny with a shout, and Goldstein took his place. Goldstein, too, had taken the lust potion. He tried to be more conscious of Ginny's pleasure, Hermione could see, but the potions the Department had provided were strong. It could invalidate an entire group's participation if someone couldn't reach orgasm. Harry didn't move away this time, continuing to touch Ginny while Goldstein fucked her fast and hard. Harry's cock was fully hard, hanging heavy and flushed between his legs, but he still made no move to gain relief. Maybe he'd learned to follow rules at some point.

Neville replaced Goldstein. To Hermione's surprise, Neville and Harry traded shark-like grins before Harry abandoned his wife to their fellow Gryffindor. Ginny didn't protest the loss, and it was quickly obvious why when Neville easily drove her to the same highs that Harry had, leaving her writhing beneath him. Harry had moved to stand beside Zabini, and based on their body language Hermione thought her friend might be coaching the Slytherin. No doubt on the finer points of Ginny's body, since Blaise Zabini had a well-substantiated reputation for having a new lover each week and certainly knew how to please a woman. 

Hermione's hand slipped between her legs, pressing against the heat of her sex. When she realized what she was doing, she pulled her hand back as though burned. She _couldn't._

Neville came, and when he pulled away Ginny looked thoroughly fucked. Cum leaked from her well-used cunt, and Blaise scooped it up and pressed it back inside her as he got into position for her first turn. Rather than pleasuring Ginny separately, as Harry had for the two men who had chosen to drug themselves, he stood beside Blaise and continued to coach. Hermione watched him nod and gesture as Zabini followed the path he was laying out to each of Ginny's sweet spots. Despite how sated the witch looked, Zabini brought her to another intense-looking orgasm quickly before coming himself. He hadn't lasted long, but he _had_ just watched from the sidelines as four different men fucked Ginny, so Hermione thought it was understandable.

It was Harry's turn again, and Hermione watched him ask Ginny a question. Apparently too breathless to speak, she responded with a thumbs-up. Harry slid his cock into his wife's pussy again, and Hermione moaned slightly at the sight. Ginny had taken five loads of cum so far, and the mingled results gave a pearly sheen to Harry's (thick, lovely, huge) cock as he took his second turn. Hermione's hand dropped to her lap again, and this time she didn't pull away. She ground against it, staring as Harry's cock disappeared over and over again inside his wife.

Hermione continued to observe as each of the men took their turns, trying to remember to watch carefully for any possible infractions, but hopelessly distracted by her own mounting lust. By the time Neville approached Ginny again, Hermione had abandoned restraint and hand her hand inside her knickers, two fingers buried in her cunt while her thumb furiously rubbed at her clit. Her other hand found its way inside her shirt as the men took their third round fucking Ginny's cunt. Hermione was never more grateful for the spells which took the place of bras as she was now, with easy access to her pebbled nipples a top priority as she chased orgasms of her own.

Before Hermione knew it, each of the men had gone four rounds and the session was over. She quickly straightened her clothing and spelled away any trace of sweat or her own sexual fluids. The bed where Ginny laid had changed shape slightly to elevate her hips, and she laid there while each of the men slipped into their robes.

Hermione stepped into the chamber with them, holding her clipboard and hoping it made her look more professional. She couldn't spell away the bright flush to her skin, but hoped it would be mistaken for an embarrassed blush.

Neither Harry or Ginny reacted to Hermione's appearance, but after the level of sexual openness and confidence she'd just seen them display she couldn't take that to mean they'd known she was the one watching.

"Thank you for your participation, everyone," she addressed the group, keeping her voice as steady and strong as possible. "In a few moments, one of my colleagues will escort each of you to the rooms you'll be staying in. I remind you that intercourse outside of scheduled sessions is forbidden at this time. You'll all be allowed to leave again once an Unspeakable has confirmed that Mrs. Potter has- successfully become pregnant." Hermione was proud of herself for only stumbling slightly over her words, given how flustered she was internally. She might tell her boss she wasn't feeling well and take the rest of the day off. 


	2. Chapter 2

Hermione blushed as Ginny and Harry entered the examination room. Ginny was just halfway through her second trimester, but she already looked very pregnant. Hermione was incapable of looking at her without being reminded of what she'd seen.

She'd watched Ginny get fucked repeatedly by the men in her group four more times before she'd gotten pregnant and they'd been allowed to leave the Department. Since then, Ginny had needed to come back once each week for a thorough examination consisting of both magical scans and hand-taken measurements. Harry came along to nearly every appointment, though sometimes his work kept him busy. The third week, they'd discovered that she was carrying sextuplets - two boys and four girls. The paternity charm went awry constantly, which suggested that the experiment had borne fruit, but nothing would be confirmed until the babies were born and could be tested for paternity individually.

Hermione's cheeks burned, and she wondered if Neville had gotten her friend pregnant while he sucked a red mark into her neck, or if Zabini's sperm had taken root in her womb while he'd gripped her hips hard enough to bruise. She remembered the way each of the men had become bolder as they'd become more familiar with Ginny's body, and how easily they'd collectively driven her wild with pleasure. She wondered, still, at how confident and comfortable Harry had been with _sharing_ Ginny. He'd been familiar with the situation, she was sure of it.

"At twenty-one weeks, you're measuring fifty-nine centimeters," Hermione told Ginny as she made a note. It was a very good thing that Ginny was a witch, and that her spells existed to provide immense support as she grew. While Ginny would surely struggle with her bulk in the coming months - she could still expect to grow as much as double her current size - she'd be able to move about anywhere space allowed for the duration. A muggle woman would be confined to her bed for her own health, but even if Ginny managed to grow as wide as she was tall the magic would keep her as active as she wanted to be.

"Hermione?" Ginny asked, breaking Hermione from her thoughts. "When you leave the Ministry tonight, we wondered if you'd come to dinner at ours?"

Hermione nodded, hoping her apprehension wasn't obvious as she cast the paternity charm and recorded its scrambled results yet again.

The house was furnished differently than the last time Hermione had visited. It was much more sparse, probably so that Ginny didn't have to worry about bumping into so many things with her rapidly expanding frame. The woman in question was using her wand to guide place settings for three to the table when Hermione arrived, while Harry finished cooking dinner. She was greeted warmly, and they were all seated in no time at all.

"Harry and I have noticed you seem uncomfortable when we come in for appointments," Ginny said over roast chicken. "Would you like us to request to work with someone else from the Department?"

Hermione was sure she was blushing again. She wasn't _uncomfortable_ , unless one counted that she often ended up in the lavatory afterward, touching herself to memories of what she'd watched. It was unprofessional, and possibly unethical, but she couldn't help herself. She hadn't reacted this way to any of the other groups. Only to her close, _attractive_ friends. In lieu of an answer, Hermione posed her own question. "Did you know, before we began, that I was the Unspeakable assigned to you?"

"I requested you, actually," Harry admitted easily. "I wanted to know that whoever watched us wouldn't be telling any stories about it to the press. The news was going to come out eventually, with Ginny being so visibly pregnant, of course. It did last week. But there were no references to the actual sex, which is what I worried about."

"Everyone in the Department takes an oath," Hermione protested weakly. Truthfully, all it took to find a way around such an oath was determination and creativity - both qualities the Unspeakables were meant to embody.

Harry glanced at her. "It wouldn't be the first time someone compromised their professional ethics in a situation involving me."

 _Did they know?_ Hermione wondered frantically. Neither of them seemed upset, and if they knew she'd been getting off on it surely they would be. Surely they'd request a transfer without consulting her. "Why did you join the study?" she asked suddenly.

Ginny and Harry looked at each other lovingly. "I want a big family," Ginny answered. 

"So do I," Harry added, "and I know better than most that blood doesn't equal family."

"I didn't think I could do what Mum did, though, and have so many children in succession. We'd already decided to use a potion to try for twins or triplets when the call was put out for participants. After talking it over, we agreed to do it. When the babies are born, I'll sign the paperwork to ensure that Harry is legally their father regardless of the paternity results. We wouldn't keep the others from them, if they want to be involved, but this is how we decided to jump start our family."

"And it didn't bother you? Having sex with the others? Being watched?"

"You're intelligent, Hermione, " Harry said wryly. "Was that our first time?" Hermione shook her head, blushing furiously. "Aside from ther possiblity of someone telling tales, no, it wasn't an issue. We've enjoyed inviting others into the bedroom... basically since the end of the war, when Neville walked in on us after the battle."

"You do it often?" Hermione asked, eyes wide.

"As often as once a week, before I was pregnant," Ginny answered cheerfully. Hermione's eyes widened impossibly further, and an all-too-familiar tension began to build in her. "I get tired more easily, now, so I tend to save my energy for Harry. We have fun with others but we love each other, you know? Although a few weeks ago we invited Blaise over for an evening."

Hermione couldn't help but press her legs together. Harry looked at her curiously, and she averted her eyes. "You aren't uncomfortable," he said slowly. "You're turned on." Hermione didn't answer, but her silence was damning on its own.

"Did you want to play our game, too?" There was heat in Harry's voice, but to Hermione's surprise it wasn't the burning heat of anger. Instead, his voice was pitched low and rough, and called to an answering heat in Hermione.

She opened her mouth to answer, but closed it when she realized she wasn't sure if she should say yes or no. Harry was offering her the opportunity to be a guest in their bed, and the look on Ginny's face betrayed her willingness, even eagerness, to let her. While Hermione had definitely fantasized about touching and being touched by both of these people, that wasn't what had dominated her mind for the last months. "I'd really like to watch you," she admitted softly.

"Who knew our favorite bookworm was a voyeur?" Ginny asked her husband teasingly. She turned to Hermione. "Did you touch yourself, watching us?"

"Yes. Yes, but only for your group." The moment Hermione had dreaded had come, but it had come in such a delicious way that she knew she had nothing to fear. She rambled on, explaining how she hadn't been able to stop herself and how even now thinking about it drove her wild with need.

"I think we ought to give her what she needs, love," Harry said to Ginny. "If you're willing and able."

Ginny just smiled coquettishly, and took Harry's hand to lead him from the table. She moved far more gracefully than she should have, thanks to the magic. A glance back towards Hermione was the only invitation they gave, but it was all she needed to follow them to the bedroom.

Hermione was only seconds behind her friends, but they'd wasted no time getting started. Her knees went weak.

Ginny was already totally naked, leading Hermione to believe they'd vanished her clothing, and perched on the edge of the large bed with her legs spread wide. She was leaned back on her elbows to keep her belly out of the way as Harry, still fully clothed, buried his face between her legs. Ginny moaned, and made eye contact with Hermione where she'd frozen in the doorframe. The sight of brown eyes darkened with arousal spurred Hermione on, and she made her way to an armchair on the side of the room to watch the show she was being given.

"Do whatever you'd like, Hermione," Harry told her when he finally pulled away. Ginny had already come once, and was panting to catch her breath. Her ample tits and hugely swollen middle both heaved with it.

"I can touch myself?" she asked without looking away from the sight.

"We might be offended if you didn't," Ginny said through labored breaths. "We're both very attractive, after all, and we've invited you for your entertainment."

Hermione needed no further encouragement, and unbuttoned the top half of her blouse as Harry encouraged Ginny into a seated position. She began to toy with her nipple beneath the shirt as Harry mouthed at Ginny's neck and ear, his hands slowly working their way up and down his wife's body. Hermione's legs pressed together of their own accord, the heat there already becoming unbearable after the casual discussion they'd had at the table, but she wanted to hold off on properly satisfying herself until her friends were further along. Harry wasn't even undressing yet.

Her oldest friend continued his slow exploration of Ginny's body and all of it's new curves and swells while Ginny stared hungrily at Hermione and threaded her fingers through his hair.

"You're so gorgeous," Harry mumbled to Ginny, easily loud enough for Hermione to hear. "You've always been stunning, but ever since leaving the Ministry you've just glowed, and I love worshipping your body as it changes. Taking care of you while you grow our family."

This was a vastly different experience from watching them in the chamber with the other men. Much more intimate. Harry gently sucked Ginny's earlobe into his mouth, drawing a moan from both witches.

He was dedicated to worshipping her body, just as he'd said, and by the time he slipped his fingers into Ginny's sex again Hermione was growing frustrated. She was determined to stick to her self-imposed rule, however, knowing it would be all the better when she finally touched herself properly for the wait. Every wank she'd had imagining them had been frenzied and guilty and this was her opportunity to draw it out and really enjoy it. Her knees were rubbing together more insistently as she continued touching her nipples and breasts just the way she liked it best. Just a tiny bit rough, but slow and deliberate.

Ginny was pulling at Harry's shirt, and he finally let her maneuver his arms away from her so that she could pull it off. The mass of her middle prevented her from reaching high enough in their current position, so Harry finished the job and shucked off his jeans and pants immediately after. His cock stood proudly, large and red and leaking precome from the tip.

Hermione slung one leg over the arm of her chair as Ginny wrapped a hand around Harry's newly-freed member and flipped her skirt up her thighs. One hand stayed in her shirt, but she finally let the other drop to rub over the top of her damp knickers.

Ginny paid less attention to Hermione as she grew absorbed in pleasuring her husband, though both she and Harry gave occasional lustful glances to their guest.

Hermione had unbuttoned her shirt completely at some point, and was grinding her cloth-covered cunt harshly against her hand when Ginny pressed Harry back against their headboard. He went willingly, taking a relaxed pose and loosely fisting his cock as Ginny moved more slowly to her desired position. The very pregnant witch straddled her husband so that both were facing Hermione and slowly sank down onto his cock.

Hermione moaned loudly as Harry's large member disappeared into Ginny's cunt, and almost frantically pulled aside her knickers to plunge two fingers into her own. 

Ginny bounced and rocked on Harry's cock with more vigor and stamina than she'd have had without the spells supporting her belly and back while two pairs of hands frantically moved from her breasts to her belly to her clit, tangling often as both of them were once again watching Hermione as she feverishly continued pleasuring herself. The wait and the wish fulfillment put her on edge, and she came twice in quick succession before she saw Harry tense and screw his face as his own orgasm approached. It was a look Hermione was familiar with by now. Her fantasies about her friends had grown much more accurate since she first watched them in the chamber.

Harry played Ginny's body like a violin, if he were a very talented violinist, and brought her to what Hermione believed was the other witch's fourth orgasm just before falling over the edge himself.

Hermione whined as Harry settled back against the headboard, pulling Ginny to rest against his chest. Hermione continued pleasuring herself furiously, but the final orgasm she desperately craved remained tantalizingly out of reach. She was nearly screaming in frustration when something caught her eye. Harry's cock, still nestled in his wife's cunt, had begun to twitch and plump back up.

"I have yet to see any evidence that you're _not_ some sort of super human," Ginny told him. Harry just grinned guiltily, and Ginny slid slowly off his lap to reveal his huge, hard cock once more. "You had me on top, so I'm utterly exhausted, but Hermione might be willing to help you out."

"Would you like that, Hermione?" Harry asked. Hermione could only nod frantically, spreading her legs wider for him. Harry was across the room in seconds, kneeling in front of the chair and positioning himself at the entrance to Hermione's cunt. She was wet and open and his cock slid in easily. Later, Hermione would wonder if they'd chosen the chair based on it being the perfect height for such a maneuver. Now, she wasn't thinking much at all.

It had been some time since Hermione had had any partner at all, and even longer since she'd had such a brilliant cock filling her up. She moaned in ecstatic relief, her legs locking around her best friend's waist of their own accord as he began thrusting into her. Harry was as talented a lover as he'd looked, but they'd never slept together before so Hermione guided him to her favorite places to be touched and he followed easily. The curve of his cock caused its head to rub against just the right spot inside her, and each time he bottomed out it put slight pressure on her cervix, and before long at all Hermione was coming again with a scream and a rush of fluids.

Hermione's legs tightened further around Harry's waist as the walls of her cunt spasmed around his thrusting cock. "I'm gonna come," Harry muttered. Hermione watched the familiar changes in his face and movements as she rode out her own aftershocks. "I'm gonna-" Harry started, louder. Before he could get the words out, they turned to a groan as his cock erupted inside her. Hot come splashed against Hermione's walls as Harry sagged against her heaving chest.

After they'd both recovered marginally, Harry pulled Hermione gently to her feet and into the bed to rest more comfortably. It wasn't until she was settled against the headboard and Harry's hand landed on her lower abdomen that Hermione realized - she hadn't used any sort of contraception.

Her eyes widened. "I- We-"

"I did try to pull out," Harry told her quietly, without rancor. "I could tell you hadn't used a charm - it feels different."

"No potion either. I'm _so_ sorry," Hermione gushed. "I just wasn't thinking."

Ginny chuckled. "Harry can do that - drive every thought from your head. It's kind of a miracle this is the first time I've been pregnant, with how often I forgot the same things before getting on the potion."

"You aren't mad?" Hermione asked, looking from Ginny to Harry and back.

"It's hardly worth being mad over an accident," Harry offered. "I guess, what happens from here happens."

Quietly, Hermione thought that she could probably get an emergency contraceptive somewhere. The magical world didn't have them, but if she made a withdrawal from Gringotts and converted it to muggle money she should be able to get to a clinic. That seemed a lot of work, though. While she knew it was logically the best choice, no one seemed to be terribly worried about it. Herself included, somewhat surprisingly.

The chances that she'd get pregnant from just one time were slim, any way.

"Que sera sera," she said quietly. What will be will be.

**Notes for the Chapter:**

> Oops this has a chapter 3 coming now.


End file.
